The CCD photometric study of the newly identified RS CVn binary star DV Piscium

This paper presents new CCD BVRI light curves of the newly discovered RS CVn eclipsing binary star DV Psc. From the asymmetric light curves outside the eclipse, we find there are two depressions in the phase ranges 0.3–0.45 and 0.6–0.9, respectively. By analyzing the light curves using the Wilson–Devinney program, the four photometric solutions of the system are obtained and the starspot parameters are also derived. It turns out that the case of two spots being on the primary is most successful in reproducing the light curve distortion of DV Psc. Moreover, analysis the longitudes of spots suggests that there are two active longitude belts (one is about 90°, the other is about 270°). At the same time, on 22 November 2008, the first flare-like event was detected on DV Psc at phase 0.35 whose duration was about 13.5 min. These findings reveal that DV Psc has a high degree of magnetic activity.     

Similarity model of feed support system for FAST

A new design of feed support system for Five hundred meter Aperture Spherical Telescope (FAST) is proposed in this paper. According to the similarity theory, a 1:15 scale model of feed support system has been built to make systemic research on the feasibility of the system. Then the control system and hardware structure of the feed support system are illustrated. A complete astronomical observation track is run by the scale model and the experiments results demonstrate that the new feed support system can satisfy the observation accuracy requirement of FAST.     

A finite element model of interaction between viscous free surface waves and submerged cylinders

This paper describes the simulation of the flow of a viscous incompressible Newtonian liquid with a free surface. The Navier–Stokes equations are formulated using a streamline upwind Petrov–Galerkin scheme, and solved on a Q-tree-based finite element mesh that adapts to the moving free surface of the liquid. Special attention is given to fitting the mesh correctly to the free surface and solid wall boundaries. Fully non-linear free surface boundary conditions are implemented. Test cases include sloshing free surface motions in a rectangular tank and progressive waves over submerged cylinders.     

An interconnect width and spacing optimization model considering scattering effect

As the feature size of the CMOS integrated circuit continues to shrink, the more and more serious scattering effect has a serious impact on interconnection performance, such as delay and bandwidth. Based on the impact of the scattering effect on latency and bandwidth, this paper first presents the quality-factor model which optimises latency and bandwidth effectively with the consideration of the scattering effect. Then we obtain the analytical model of line width and spacing with application of curve-fitting method. The proposed model has been verified and compared based on the nano-scale CMOS technology. This optimisation model algorithm is simple and can be applied to the interconnection system optimal design of nano-scale integrated circuits.     

The Structure of Potential Amur Tiger (Panthera tigris altaica) Habitats and Evaluation of Its Prey in Taipingou National Reserve (China) Based on Remote Sensing Data

Izvestiya, Atmospheric and Oceanic Physics - The population of the Amur tiger (Panthera tigris altaica) in the Russian Far East is currently being restored; young individuals are being spread...     

A System for Fast Cartographic Sounding Selection

Soundings on nautical charts provide information about the shape of the ocean bottom between chart depth curves. A single chart may have thousands of soundings posted on it. This article describes a system for automatic cartographic sounding selection. In this system, a new algorithm for automated selecting soundings is developed. The algorithm is employed in such a way that it can guarantee (a) fast and accurate selecting sounding, (b) processing the circular depth curves, (c) solving the overplotting problems between depth curves and soundings, and (d) keeping selected soundings “prettier.” The system was intensively tested using real data sets, and its superiority has been revealed by the testing results.     

壳聚糖/纳米铜复合微球的制备及其对刚果红染料的脱色性能

以壳聚糖和CuCl₂·2H₂O为原料,分别采用直接负载法和吸附法成功制备了壳聚糖/纳米铜复合微球,运用傅里叶变换红外光谱(FT-IR)、X-射线衍射(XDR)和扫描电镜(SEM)对催化剂结构进行了表征。以刚果红(CR)染料为目标污染物,评价了催化剂的制备方法、制备条件及氢转移催化反应条件对其催化性能的影响。结果表明,由直接负载法(CS/CuNPs)和吸附法(CS/CuNPs-X)制备的壳聚糖/纳米铜复合微球在CR染料浓度为100 mg/L,催化剂投加量为0.05 g,供氢体浓度为0.05 mol/L的氢转移催化反应条件下,催化反应进行180和60 min时CR脱色率可分别达95.8%和96.8%。CS/CuNPs-X比CS/CuNPs表现了更高的对CR氢转移催化反应的催化速率。两种催化剂催化还原CR染料的反应均符合准一级动力学模型。在连续循环使用10次后,CS/CuNPs和CS/CuNPs-X对CR的脱色率分别为93.9%和89.4%,表明催化剂具有良好的重复使用性能。     

Last glacial terrestrial vegetation record of leaf wax n-alkanols in the northern South China Sea: Contrast to scenarios from long-chain n-alkanes

Long-chain n-alkanols and n-alkanes in core sediments from the northern South China Sea (SCS) were measured to make a comparison during terrestrial vegetation reconstruction from ~42 ka to ~7 ka. The results showed that terrestrial vegetation record from long-chain n-alkanes matched well with previous studies in nearby cores, showing that more C₄ plants developed during the Last Glacial Maximum (LGM) and C₃ plants dominated in the interglacial period. However, these scenarios were not revealed by terrestrial vegetation reconstruction using long-chain n-alkanols, which showed C₃ plant expansion during the LGM. The discrepancy during the interglacial period could be attributed to the aerobic degradation of functionalized long-chain n-alkanols in the oxygen-rich bottom water, resulting in poor preservation of terrestrial vegetation signals. On the other hand, the different advantages of functionalized n-alkanols and non-functional n-alkanes to record local and distal vegetation signals, respectively, may offer a potential explanation for the contradiction during the LGM when the SCS was characterized by low-oxygen deep water. Nevertheless, large variations on n-alkyl lipid compositions in C₃/C₄ plants could play a part in modulating sedimentary long-chain n-alkanols and n-alkanes toward different vegetation signals, thereby suggesting that caution must be taken in respect to the terrestrial vegetation reconstruction using long-chain n-alkanes and long-chain n-alkanols.     

A unified constitutive model for cemented/non-cemented soils under monotonic and cyclic loading

Acta Geotechnica - In this paper, an elastoplastic constitutive model is proposed to uniformly describe the mechanical behavior of cemented/ non-cemented soil under different loading conditions. A...     

Energy transfer among Pb, Ce and Mn in fluorescent calcite from Kuerle, Xinjiang, China

Natural calcite from Kuerle, Xinjiang, China, shows orange-red fluorescence when exposed to short-wave ultraviolet (UV) light (Hg 253.7 nm). Photoluminescence (PL) emission and excitation spectra of the calcite are observed at room temperature in detail. The PL emission spectrum under 208 nm excitation consists of three bands: two UV bands at 325 and 355 nm and an orange-red band at 620 nm. The three bands are ascribed to Pb²⁺, Ce³⁺ and Mn²⁺, respectively, as activators. The Pb²⁺ excitation band is observed at 243 nm, and the Ce³⁺ excitation band at 295 nm. The Pb²⁺ excitation band is also observed by monitoring the Ce³⁺ fluorescence, and the Pb²⁺ and Ce³⁺ excitation bands, in addition to six Mn²⁺ excitation bands, are also observed by monitoring the Mn²⁺ fluorescence. These indicate that four types of the energy transfer can occur in calcite through the following processes: (1) Pb²⁺ → Ce³⁺, (2) Pb²⁺ → Mn²⁺, (3) Ce³⁺ → Mn²⁺ and (4) Pb²⁺ → Ce³⁺ → Mn²⁺.